encapsulate the max_drift into the Target so it is open to customization

app/models/target.py

@@ -6,3 +6,11 @@ class Target(BaseModel):
     value: float
     result: Optional[float]
     drift: float = 0.0
+
+    @classmethod
+    def max_drift(cls):
+        return 10 # 10% elasticity
+
+    @classmethod
+    def max_drift_increment(cls):
+        return 1 # 1%

app/services/loft_service.py

@@ -9,6 +9,7 @@ from models.solver_run import SolverRun
 from models.solution import Solution
 from models.form import Form
 from models.item import Item
+from models.target import Target
 
 from services.base import Base